Not Applicable
Not Applicable
The present invention relates to battery powered, fan-driven volatile dispensers.
The art has produced a variety of fan-driven devices for dispensing volatile materials into the air. Typically such devices include a housing, an air inlet and outlet with an airflow path extending therebetween, a fan to produce an airflow in the airflow path, and a variety of means for introducing the volatile materials into the airflow path. A number of these fan-driven devices utilize battery power to drive the fan.
Of particular relevance to the instant invention are such battery powered devices that utilize a replaceable cartridge or refill assembly for renewing the supply of volatile materials to be dispensed by the device. Dancs et al., U.S. Pat. No. 5,547,616 and Ito et al., European Patent Application, EP 0775441 are specific examples of such devices. The disclosures of these patents and all other publications referred to herein are incorporated herein by reference as if fully set forth.
An important problem for a user of a battery-powered, fan-driven, volatile dispensing device is detecting when either the battery or the volatile material is depleted. A low voltage battery may still turn a fan, for example, but only at a reduced rate so that an inadequate amount of the volatile ingredient is dispensed. Similarly, the volatile supply may be used up before the battery is depleted, with the same result of inadequate amounts of volatile being dispensed. If the volatile ingredient is an air scent, a user might be able to detect inadequate dispensing simply by noticing a reduced amount of scent in the air. However, it can be difficult to notice a lowered level of a volatile when the volatile is an essentially odorless insect control agent.
Muderlak et al., U.S. Pat. No. 5,175,791 uses a timer circuit to step up power over time to the heater utilized to cause the active ingredient to be dispensed. The Muderlak et al. ""791 device is not battery driven, does not utilize a fan, and is noted only for its general use of a timer circuit to adjust dispenser function in response to anticipated volatile depletion. Kunze, U.S. Pat. No. 5,370,829, discloses timed operation of a battery-driven fan. However, the timer appears not to be designed to measure or respond to consumption of either battery power or volatile ingredient.
Walz et al., U.S. Pat. No. 4,840,770, does not include a timer or indicator device but does utilize an amount of a gel-like odor control product selected to be sufficient that battery life and the life of the volatile ingredient are about the same. As a consequence, the xe2x80x9cproduct and battery can be installed and replaced at the same time as a unit, thus assuring that an old battery is not left in by mistake.xe2x80x9d (Column 7 at Lines 49-52). However, Walz et al. does not teach any effective use-up cue or other response to a partially depleted battery that is may still be capable of turning a fan but only at an inadequately slow rate.
Sullivan et al., U.S. Pat. No. 4,276,236 and Tringali, U.S. Pat. No. 4,035,451, both disclose a cylindrical cartridge having a conventional, cylindrical battery held at the longitudinal axis of the cartridge, with a space between the battery and the outer wall of the cartridge holding a fluted strip of paper bearing active ingredient. The battery is integrally fastened within the cartridge. The Tringali and Sullivan cartridges permanently mount the battery within the same cartridge that carries the device""s supply of volatile ingredient. Although no use-up indicator is supplied, at least the battery and volatile material must of necessity be replaced at the same time.
The Dancs et al device does directly address the issue of a battery depletion cue, relating it to volatile use-up. It uses conventional, replaceable batteries, such as D-cells, and a replaceable refill assembly bearing a finite quantity of volatile active ingredient to be dispensed. Volatile active ingredient is loaded on the refill assembly in an amount calculated to be depleted approximately upon the passage through the air flow path of that volume of air that the device""s fan will deliver before an initially fresh battery is discharged below a selected level. Thus, depletion of the battery corresponds with active ingredient depletion and signals the need to replace both the battery and the refill assembly.
The Dancs et al device uses a control circuit to sense the condition of the battery, preferably by responding to voltage drop. The control circuit turns off the power to the fan when the battery condition reaches the level that should correspond to or just anticipate active ingredient depletion. The Dancs et al control circuit includes an LED or other small signal light that either is on or off to provide a visual cue to the user that the battery is being drained to a level approaching that at which power to the fan will be turned off. Consequently, a user of the dispensing device is given advance warning of device shut down.
The Dancs et al visible use-up cue can be effective but does present certain disadvantages. It requires a relatively expensive, specialty control circuit that must perform multiple tasks, sensing battery condition, actuating a light, and (eventually) cutting power to the fan. The light can be difficult to see in daylight or other well-illuminated conditions. Even when it is visible, the significance of the light""s condition can be ambiguous, confusing a user. For example, does an illuminated red light signal that the device is running or that it is about to stop running? Multiple lights are possiblexe2x80x94for example green to indicate that the device is operating and red to indicate an approaching motor turn-off. However, the necessary control circuits and lights add considerable cost to the device.
The art thus is aware of various control mechanisms in fan volatile dispensers, control mechanisms that provide use-up indicators or timing circuits to measure the use or indicate the depletion of either the battery or the volatile material being dispensed. However, such devices typically require lighting circuits for visual cues or provide no affirmative power cut-off prior to a fan""s inadequate operation owing to low battery voltage.
Various other devices are believed to exist in the art, and those referred to, above, are by way of example only. A need still exists in battery-powered volatile dispensers for dispensing volatiles for an economical, simple, visually obvious cue for volatile supply use-up, combined with detection of and a visual cue for battery levels inadequate to run a fan at a speed or with a power sufficient to dispense a desired amount of volatile.
The following definitions apply herein:
A fan is defined herein as being xe2x80x9cunrestrictedly visiblexe2x80x9d if it is visible to a user viewing the volatile dispenser from the front when the volatile dispenser is in its normal position of use, without the presence of a visually obstructing grid or similar structure and without the need to remove any part of the volatile dispenser or any volatile reservoir used with the volatile dispenser. A grid or similar structure will be deemed xe2x80x9cvisually obstructingxe2x80x9d if it prevents a viewer from observing more than 40, preferably not more than 30, and most preferably more 20 percent of the fan. Ideally, there is no grid or similar structure at all.
A xe2x80x9cvisual cuexe2x80x9d is a visually detectable change in appearance that serves as a signal to the observer. A xe2x80x9cprominentxe2x80x9d visual cue in a device is a visual cue that is apparent to a user of the device upon even casual observation under the lighting and distances characteristic of typical daytime use or inspection conditions.
An xe2x80x9ceffectivexe2x80x9d level or xe2x80x9ceffectivexe2x80x9d amount is that level or amount sufficient to achieve the desired purpose.
A fan is operating at a xe2x80x9cdispensing speedxe2x80x9d if its speed is sufficient to create an air flow in an amount effective to dispense volatile from the volatile reservoir in the amount desired.
The invention provides a battery powered volatile dispenser for dispensing a volatile material. The volatile dispenser has a housing having an air inlet, an air outlet, an airflow path therebetween, together with a holder for a volatile reservoir for supplying a volatile to be introduced into air flowing in the airflow path. A fan is included that is adapted to be powered by a battery. The fan is so located that it propels air through the airflow path and also is unrestrictedly visible to a user of the volatile dispenser.
The volatile dispenser of the invention also has an electrical power cut-off that activates to cut off power to the fan when the battery voltage drops beneath a selected level greater than zero. Because the fan is unrestrictedly visible to a user of the volatile dispenser, cutting power to and thereby stopping the fan provides a prominent visual cue of battery depletion.
Preferably, the volatile dispenser is adapted for use with a replaceable volatile reservoir having a known quantity of volatile available for dispensing. The preferred volatile reservoir includes a substrate releasably bearing the volatile to be dispensed, preferably held in a frame or other structure that facilitates handling. The xe2x80x9crefill assemblyxe2x80x9d and associated xe2x80x9csubstratexe2x80x9d disclosed in Dancs et al., U.S. Pat. No. 5,547,616, is suitable and is preferred. The battery voltage level beneath which the electrical power cut-off activates is the battery voltage level remaining after the fan has run sufficiently long to reduce the quantity of volatile in the reservoir to a selected level. Consequently, the cut-off of power, Which stops operation of the fan, provides a prominent visual cue for volatile depletion to the selected level. It is further preferred that the electrical power cut-off activates to cut off power to the fan at a battery voltage level still effective to power the fan at a dispensing speed.
In another preferred embodiment, the fan of the volatile dispenser is a propeller blade-type fan having a hub and radially extending blades, with the fan being sufficiently contained within a well to substantially prevent a user from touching the tips of the fan from a direction radial to the hub. Most conveniently, the well is formed as a part of the housing.
In yet another preferred embodiment, the housing of the volatile dispenser has a bottom surface and a door located in the bottom surface through which a battery may be inserted to power the fan. The housing is so formed that the door must be closed before the housing can be set in its position of use, with the weight of the volatile dispenser substantially resting on the door.
It is further preferred that the housing of the volatile dispenser have a bottom surface and that the volatile dispenser be taller than the smaller of the front-to-back and side-to-side dimensions of the bottom surface, so that the volatile dispenser presents an upright, relatively slender and tall appearance. The volatile dispenser further preferably includes a battery holder located within the housing and positioned to hold a battery adjacent to the bottom surface, effectively lowering the center of gravity of the volatile dispenser when a battery is in place in the holder. This arrangement increases the stability of the volatile dispenser when it is resting on its bottom surface. Preferably, the volatile dispenser includes a door located in the bottom surface of the housing through which a battery may be inserted into the battery holder, the housing being so formed that the door must be closed before the housing can be set in its position of use. Further, it is preferred that the door must be closed to retain a battery in the battery holder when the volatile dispenser is oriented in its position of function.
The method of the invention of signaling a user of a battery powered volatile dispenser for dispensing a volatile material from a reservoir of the material that the reservoir has been depleted to a selected degree is summarized as follows. As one step, the person performing the method must provide a reservoir of the volatile material, the reservoir having a known capacity and known volatile delivery characteristics.
As another step, the person performing the method must provide and install the reservoir in a battery powered volatile dispenser capable of dispensing volatile material from the reservoir and having (i) a fan adapted to be powered by a battery, the fan being so located that it propels air along an airflow path to pick up the volatile material from the reservoir, the fan being unrestrictedly visible to a user of the volatile dispenser; and (ii.) an electrical power cut-off that activates to cut off power to the fan when the battery voltage drops beneath a selected level greater than zero, the voltage level being calculated to be the battery voltage level remaining after the fan has run sufficiently long to reduce the quantity of volatile in the reservoir to the selected degree, so that the cut-off of power, which stops operation of the fan, provides a prominent visual cue for volatile depletion to the selected level.
The final step is to activate the volatile dispenser and observe the movement of the fan. A preferred added step is to select the battery voltage level at which the electrical power cut-off activates to be a voltage level still effective to power the fan at a dispensing speed.